No. 105 

1960 

SEASONAL GROWTH IN WHITE PINE SEEDLINGS 

FROM DI FFERENT PROVENANCES 

The Northeastern Forest Experiment St at ion, in cooperation with other experiment stations in the United States 

and Canada, began a range-wide provenance test of eastern 

white pine- (Pinus strobus L.) in 1955. Seed was collected 

from 31 different locations in 17 states and 4 Canadian provinces. In most places collections were made from 10 trees 

at each location. The seed from individual trees was kept 

separate. 

Twenty-one of the test provenance seedlots (table 1) 

were grown at the New Jersey state nursery at Washington 

Crossing, N. J. Seed for this test was sown in the fall of 

1956. Each mother-tree lot occupied 1 bed-foot (1 foot by 

3 feet). The seedlings were thinned to about 35 per square 

foot in July 1957. 

During the 1959 growing season periodic measurements 

of height growth were made on selected seedlings of this 

test. Three mother-tree lots were randomly selected within 

each provenance and five seedlings were chosen from each lot. 

Thus 15 seedlings of each provenance were measured. Bud 

swelling and elongation started in all provenances on or 

about April 17. Height growth was measured thereafter at 

approximately weekly intervals until July 13. Measurements 

were made with a steel millimeter tape from a fixed point, 

usually the axil of a lateral bud or branch. 

Variables that were studied included: (1) duration of 

the growth period up to the base of the terminal bud; (2) 

total growth from the tip of the 1958 terminal bud to the 

base of the 1959 terminal; (3) total growth from the tip of 

the 1958 terminal bud to the tip of the 1959 terminal or 

lammas shoot ; and (4) the percentage of tip-to-base growth 

completed by May 18. These data are given in table 2. 
Table 1.--Description of eastern white pine seed sources 

Seedlot State 

or County Latitude Length of * 

designation province growing season 

(Days) 

I GA Georgia Union 34' 46 ' 2 05 

2NC North Carolina Transylvania 35"14 ' 170 

3TE Tennessee Greene 36'00' 187 

4MD Mary 1 and Garrett 39'24 ' 133 

5WV West Virginia Greenbrier 38" 00 ' 150 

6PA Pennsylvania Monroe 41" 05 ' 127 

7PA Pennsylvania Monroe 40'55 ' 144 

8PA Pennsylvania Clearfield 40°46 ' 139 

9PA Pennsylvania Clearf ield 40'46 ' 139 

1 ONY New York Ulster 42'00' 160 

1 lNY New York Ulster 42' 05 ' 160 

12NY New York Franklin 44'25' 99 

13MA Massachusetts Worcester 42"30' 153 

14ME Maine Penobscot 44'51 ' 142 

15IA Iowa Allamakee 43" 18' 149 

160H Ohio Ashland 40'45 ' 157 

18WI Wisconsin Forest 45"40f 123 

19MN Minnesota Cass 47'25 ' 120 

2 0NS Nova Scotia Lunenburg 44'25 ' (**I 2 1NB New Brunswick Sunbury 45" 56 ' (**I 

22QU Quebec Quebec 46'29 ' (**) 

*~ata from Climate and Man, U. S. Dept. Agr. Yearbook, 1941. ** No data available for Canadian sources. 

Table 2 .--Growth data for eastern white pine provenances 

* Seedlot Duration Tip-to-base Tip-to-tip Tip- to-base 

growthcompleted designation of growth growth growth by May 18 

- Days Percent - ~m . - Mm . 1GA 51.5 59.8 249 271 

2NC 47.8 63.8 2 09 225 

3TE 48.5 67.9 2 02 246 

5WV 46.9 70.0 190 2 04 

4MD 46.9 70.7 2 08 224 

160H 47.3 68.5 2 07 222 

8PA 44.5 77.9 158 171 

9PA 44.5 71.7 2 06 223 

7PA 45.0 72.9 159 173 

6PA 45.0 72.1 181 196 

lONY 43.1 77.6 163 177 

1 lNY 44.5 78.1 198 215 

13MA 45.0 77.7 196 214 

15IA 45.0 73.7 189 2 03 

12NY 42.2 85.4 145 161 

20NS 37.4 91.4 126 161 

14ME 43.1 79.9 179 197 

18WI 39.9 86.6 116 129 

21NB 37.1 92.7 123 144 

22QU 36.6 95.3 92 111 

19MN 37.5 90.3 106 128 

*seedlots are listed here in order of increasing latitude. 

2 
Active terminal height growth continued until June 8 

in the Georgia and North Carolina seedlots whereas the Canadian seedlings and some tree-lots from Minnesota and Wisconsin had ceased their initial elongation by May 25. The trees 

were not measured between July 13 and August 20, during 

which time the terminal buds were set and all lammas growth 

took place. Thirty-four seedlings exhibited lammas growth 

in 1958 and 43 trees showed this second growth flush during 

1959. Seventeen trees had lammas growth in the terminals in 

both years. Although there was a tendency for seedlots of 

southern origin to have a higher percentage of seedlings 

with lammas growth, none of the North Carolina trees showed 

this characteristic, whereas seven of the Nova Scotia seedlings had a second growth flush in 1959. 

The data for the four growth variables were subjected 

to analysis of variance and in all cases highly significant 

differences were found between provenances. Furthermore, 

when the four growth variables were correlated with latitude 

and growing season of origin, all correlations were highly 

significant. Thus a seedlot from the southern part of the 

range in an area with a relatively long frost-free season 

APRIL 17 APRIL26 MAY 4 MAY I1 MAY 18 MAY 25 JUNE I JUNE8 JUNE 15 

Figure 1. --Cumulative tip- to-base qowth for two northern 

and two southern seed sources of eastern white pine, at 

approximately weekly intervals. 
grew for a longer period of time in the nursery and also to 

a greater height than seedlings of northern origin. Superiority in height growth of southern sources has also been 

shown in similar nursery tests in New York and Maryland. A 

comparison of the seasonal growth pattern for two northern 

and two southern seed sources is given in figure 1. 

The variation between provenances in length of growth 

period, and in percentage of tip-to-base growth completed by 

May 18, appeared to be of a continuous nature when the data 

were analyzed by a multiple range test (a test designed to 

permit comparisons of means from different points in the 

array). The total growth figures, on the other hand, showed 

marked discontinuities. However, since only 1 year's growth 

was measured and the variation between mother trees within 

provenances was large, these discontinuities may have no 

biological significance. 

The fact that active terminal growth in all provenances had stopped prior to the longest day of the year suggests that the duration and cessation of height growth in 

Pinus strobus is not under direct photoperiodic control. 

Seedlings of southern origin may be able to utilize a greater portion of the growing season in northern latitudes than 

those of northern origin and still remain capable of hardening off in time to escape damage by early frost. The question whether this juvenile superiority of southern stock 

will continue throughout the life of the tree will be answered by future observations on the many test plantations 

now being established. 

--IRANK S. SANTAMOUR, JR.~ 

Geneticist 

Northeas tern Forest Experiment Station 

Forest Service, U.S. Dept . Agriculture 

'stationed at the hbrris Arboretum, Philadelphia, Pa., where the Northeastern Station conducts forest genetics research in cooperation with the Chiversity of Pennsylvania. 

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